1. Technical Field
This invention relates to apparatus for transportation of banknotes in tamper-proof carriers.
2. Related Art
It is known to provide portable banknote carriers into which notes can be inserted but not subsequently withdrawn without leaving evidence that there has been tampering. Carriers of this type are commonly used at tills where, for security, cashiers can insert banknotes when the stack of notes in a till exceeds a particular level, then at periodic intervals or the end of the day the carriers are locked, removed from their location at the till, marked with the till identification and handed over for counting and banking.
With such a system it is not necessary for the cashier to count the money put into the carrier because it will be evident if there had been tampering after the carrier has left the till. Nowadays it is often preferred for the carriers to be counted at an ‘out of house’ central accounting location or bank that may be remote from the original cashier's location. The carrier may be handled by individuals from different organisations such as security transportation firms. Thus, as well as requiring resistance to tampering, the carrier and its lid are preferably lightweight and recyclable, due to the cost and inconvenience of returning carriers.
Published European Patent Application EP-1314144-A describes one such system, in which a carrier is locked in place in a support structure for receipt of banknotes and when it is required to remove the carrier this can only be done after a tamper-proof lid has been inserted over the carrier. The mechanism is designed so that during the procedure of attaching the lid and subsequent removal of the carrier from the supporting structure it is not possible to remove notes. The lid slides over the carrier in one direction only and there are end stops that lock when the lid is fully engaged, and at that point release from the support structure is enabled. Access to the carrier requires breakage of the end stops so that the lid can be slid, in the same single direction, off the carrier at the opposite end from which it was introduced.
It has been found that the channels of the lid and carrier top, when made thin or of some plastics materials, have sufficient flexibility for them to be prized apart and notes removed without leaving evidence of tampering. It is desirable to make sure this cannot happen without having to make the relevant parts of thicker or different materials. Indeed it is preferable to be able to make the parts thinner in some instances, or of more easily recyclable materials.